The biggest EV question: Where are you going to plug in?

The logistics of charging EVs is as complicated as the batteries

EVgo is one of the companies hoping to cash in on the future of EV technology.

Youtube and Vimeo Url

A reliable public charging infrastructure will be key to fostering the growth of electric vehicles — even if those chargers don't get used much.

The U.S. Alternative Fuels Data Center's most recent numbers show 16,457 EV charging stations, with 44,999 outlets in operation, mostly on the coasts, but also including Tesla's network of Superchargers along major intercity corridors and other superfast charging stations.

The presence and visibility of these stations should help build confidence among consumers thinking about buying battery EVs that they will be able to charge wherever they want.

But once people live with an EV, they often realize they don't need access to public chargers as much as they once needed public gasoline stations, or require the same kind of quick fill-up.

After all, millions of Americans have some basic form of charging infrastructure in their homes. They plug in overnight, just as they do with their smartphones, and top up at other times when they're home or out running errands.

"The life of an EV driver is distributed charging," said Tony Canova, COO for Charge-Point, which operates a network of public charging stations and sells home charging equipment. "We've all gotten used to living in a world where a gas tank is 15 to 25 gallons. We haven't figured out yet that a car just needs enough juice to live your life."

In this way, resolving the lingering infrastructure questions facing EVs will require more than just replicating the ubiquity and format of the filling station. As with the advent of autonomous cars or new ownership models, the EV movement will involve addressing broader questions about how consumers use their vehicles and their time.

One glance at the US Light Vehicle Sales and North American Production numbers thus far this year should signal to even the most casual of observers—the slope has flattened. It was a strong run.

Canova said people with predictable commutes will get along fine with home and workplace charging, eschewing public charging altogether. Some drivers in a fleet or taxi environment (or riders, in an autonomous vehicle) may need access to higher-speed charging to keep their vehicles on the road longer.

"But that doesn't mean that all high-speed charging needs to be a five-minute charge," he said.

There are three main ways to charge an EV:

1. At home, using a conventional 120-volt household socket.

2. With a Level 2 charger, a faster 240-volt unit that's used for most public and workplace chargers but also can be installed in homes.

3. With a DC fast charger, the fastest but scarcest option; there are just 2,183 of them, including Tesla's Superchargers, and not all EVs are compatible.

Related

In 1996, SAE International approved and then updated a newer standard connector, called J1772, which all EVs built today can accept (Tesla EVs require an adapter) and which is the plug on most public chargers (again, Tesla is the exception).

So while vehicle and charging station capacities vary, for the most part, the EV market has its equivalent of the USB charging cables used for smartphones — a standard, which is one of the key building blocks of widespread infrastructure.

Tesla is the only automaker with its own network of high-speed chargers, and none of them offers a five-minute fill-up. Instead, the Superchargers can refill a Tesla battery from nearly empty to about 80 percent full in 20 to 30 minutes. The network is designed to make long-distance road trips practical in an EV and help drivers make the most of their charging time.

Tesla's Supercharger website touts the stations' ability to "get you back on the road quickly" and says they "are located near restaurants, shopping centers, and Wi-Fi hot spots." Tesla declined to comment for this report.

Terry O'Day, vice president of product strategy and market development at EVgo, a charging station network operator, said putting chargers where people are naturally going to spend time has been a good model for today's EVs.

O'Day has been keeping an eye on what Tesla is up to. "Tesla has always been a step ahead because they started early, because they have a lot of vision and because they are focused only on building electric cars," he said. "So there's a lot to learn from how they're thinking."

Related

Specifically, O'Day pointed out that with its longer-range EVs, Tesla could focus on building its early Supercharger stations in the "corridor" locations between cities. That meant there was more room to build, and real estate was usually less in demand.

"All they had to do was intercity," he said, "whereas we were building for everyone else."

EVgo stations are mostly Level 2 chargers in urban and suburban locations such as shopping centers or movie theaters, where consumers can expect to while away a few hours.

But as the EV market evolves to include ever more models with more powerful batteries, longer ranges and higher charging "acceptance" rates, chargers will need to evolve, too. So, too, will assumptions about the best locations and typical usage patterns.

Today's "fast" charging stations commonly offer rates of 50 or 60 kilowatts, which translates into roughly 100 miles of range in the battery per hour, even though batteries hooked up to a fast charger are programmed to stop accepting the full power once the battery reaches about 80 percent full. A step down from that, a Level 2 public or home charger, might offer 100 miles in 10 or 12 hours.

The new generation of EVs, though, will be able to charge at rates up to 350 kW — potentially getting 250 miles of range in about 15 minutes. The Porsche Mission E, due in 2019, is the first announced vehicle to be compatible with the higher rate, and there are unnamed others scheduled to arrive in 2020 and beyond.

Is fastest best?

Some EV advocates point to the DC fast chargers as the way of the future — shorter charge times mean that EVs can be used more like gasoline-powered cars.

But chances are, they will only be a part of the EV ecosystem alongside the slower, more common charging instead of supplanting them.

That's because most EV drivers will still only need and use the stations that make the most sense to them, whether that means at home, at work or between cities.

In some cases, the current stations will need to be replaced, which won't be easy, said O'Day. "It's a massive undertaking. In a few cases, we will be able to go from 50 to 350 [kW], and in some cases we can go to 150," he said.

Related

EVgo is planning ahead, though. "For the new stations that we're designing," O'Day said, "where possible, we're reserving the power capacity required to serve those higher levels and laying out the stations so that all it will take is a booster in the back of the stations so that you can get up to the higher level."

To handle the extra power, a station would need space for a box roughly the size of a Sub-Zero refrigerator. Not many EVgo stations installed today have room for that, and many shopping centers wouldn't want it there anyway.

"At those retail centers, parking is at a premium," O'Day said. "A store manager will tell you how much revenue they generate per day or per month per parking space, so taking up parking space with a couple of refrigerators is not that attractive to them.

"But at the higher charging levels, we might be mimicking more like the gas station experience," he said.

At ChargePoint, Canova says to expect EVs and infrastructure to develop in tandem, with upgrades to the infrastructure reflecting and enabling more capable vehicles, just as the Internet has evolved in speed and capability to handle more sophisticated communications.

"Infrastructure is what enabled the Internet to occur," he said. "Infrastructure is what is going to enable this transformation in transportation to occur."